Surgical instrument

ABSTRACT

A surgical instrument for performing endoscopic surgical procedures. In one embodiment, the instrument includes a knife that remains unexposed until initiation of a cutting sequence, and returns to an unexposed position at the conclusion of the cutting sequence, minimizing the risk of injury to the person handling the instrument. In another embodiment, the instrument includes a flexible neck for articulating a surgical head assembly with respect to the shaft of the instrument. In another embodiment, a device for locking the articulated head at an angle of articulation is provided. In yet another embodiment, a mechanism for opening and closing an anvil assembly is disclosed.

This is a division of application Ser. No. 08/359,107, filed Dec. 19,1994, pending, which is hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates generally to medical engineering, and morespecifically it relates to laparoscopic or endoscopic surgery. Mostspecifically, it relates to a surgical instrument which/may bearticulating, having improved articulation capability, including anarticulation lock and improved articulation connections, may be capableof performing clamping, closures and cutting of lumen and tissue, andmay include a safety wedge/sled that provides a safety for knifeprotection once a cutting sequence is completed. This is accomplished ina mechanism which can be used endoscopically, that is through a trocarcannula or alone, through an incision.

BACKGROUND OF THE INVENTION

In recent years surgery has markedly advanced through the performance oflaparoscopic and endoscopic surgical procedures such ascholecystectomies, gastrostomies, appendectomies, and hernia repair.Also, the application of endoscopic surgical stapling and suturinginstruments has been provided in cardiovascular and pulmonary surgery,as well as operative inventions in the gastrointestinal tract. Suchendoscopic instruments are capable of providing hemostasis and also ofcutting tissue. This reduces operating and recuperation time. Thesestapling procedures are accomplished through a trocar assembly, which isa surgical instrument used to puncture a body cavity. The trocarcontains a sharpened obturator tip and a trocar tube or cannula. Thetrocar cannula is inserted into the skin to access the body cavity, byusing the obturator tip to penetrate the skin. After penetration, theobturator is removed and the trocar cannula remains in the body. It isthrough this cannula that surgical instruments are placed. Specifically,it is through this trocar cannula that surgical stapling instrumentswith cutting mechanisms are placed. One such trocar is the Endopath®trocar manufactured by ETHICON ENDO-SURGERY, Cincinnati, Ohio.

Nonetheless, certain deficiencies in current concepts for endosurgicalstapling, cutting, clip applying, and grasping mechanisms have beenrecognized. One perceived deficiency in current surgical articulatinginstruments is that when loaded, the articulating head on the instrumenttends to move. This movement is usually a combination of piece partdeflection and slop (or backlash) in the articulation mechanism. Highloads on the distal tip of the instrument (e.g., tissue clamping andstaple firing) are reflected through the articulation device into thearticulation control near the handle and can move (or rotate) thearticulation control mechanism. In the past, articulation joints weredesigned with the articulation device performing double duty as themeans for both positioning and locking the articulated head of theinstrument.

An examination of the force application points for the load (tip of theinstrument) and the articulation device (near the articulation joint)reveals a mechanical disadvantage for the articulating device. Thisdisadvantage manifests itself as a magnification of tolerances orclearances in the articulating device, resulting in significant headmovements.

In existing articulating surgical instruments, the rigid shaft of theinstrument is sometimes pivotally connected to the surgical head of theinstrument with a pivot mount, such as a pin, hinge, or other jointmechanism. While such mechanisms offer the advantage of a precise, tightbend, this same advantage creates a perceived disadvantage, in thanincreased transmission force may be required in order to drive asurgical tool, such as a knife, around a tight bend, which force ismagnified as the angle of articulation increases.

Wedge sled and knife assemblies are generally known in the art. Ingeneral, however, such assemblies are not self-contained within thestaple cartridge, rely on more expensive metal, as opposed to plasticwedges, present problems of cutting and stapling in an axis which is notcolinear with the shaft, present technical difficulty associated withincorporating a spent cartridge lockout in an articulating joint, do notprovide a new knife for each firing, and may not completely contain thesharp edge of the knife within the cartridge at the initial and finalpositions of the linear cutting procedure, creating the potential forinjury to the user.

A design criteria in creating a system containing two separatemechanisms for clamping and firing tissue is the limitation of the humanhand. Therefore, it is difficult to properly and conveniently position apair of triggers or a pushbutton mechanism coupled with a triggermechanism. Thus, there has been little focus or incentive to createstapling mechanisms whereby the user is capable of operating a staplerwith two strokes, unless both can be accomplished in a one-handedoperation without moving that hand from the handle of the instrument.

Naturally, it would be desirable to be able to perform these functionsin a fully rotational system. This simply allows the user to obtainvirtually any angle of approach to the surgical site without having tocontort the arm of wrist in order to adequately approach the subject.

Furthermore, it would be advantageous to provide the capability toremotely articulate the surgical, e.g., clamping and stapling end of theinstrument, such that the angular orientation of the end of theinstrument may be adjusted even after the instrument has been insertedthrough the cannula.

It is also desirable to have distal contact of the stapling jaws, andthen proximal clamping. "Distal contact" means that the distal or farend of the anvil seats first on the gap spacing pin or cartridge.Without such distal contact, the surgeon may still be uncertain aboutthe amount of tissue clamped, and therefore the firing force necessaryto fire the mechanism. In this way, once distal contact is effectuated,the surgeon realizes and can actually visualize, through anendoscopically placed camera, the amount of tissue clamped between thejaws. Also, distal contact helps prevent tissue from slipping out of thejaws during a clamping sequence.

Additionally, it would be advantageous to provide a knife assembly thatincluded a safety feature, whereby following a cutting sequence, theknife retracts or otherwise is shielded from the operator of theinstrument, reducing the likelihood of an inadvertent cutting of thepatient or the operator.

Also, it would be highly desireable to provide a device for locking thehead of an articulating surgical instrument in an articulated position.

Finally, it would be useful to provide an articulation connection havinga flexible neck connecting the rigid shaft of the surgical instrument toa surgical head assembly, providing for a smoothly radiused bend,allowing smoother transmission of force around the bend than is possiblewith sharper bends achieved through an articulation joint.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a stapling mechanism whichis able to be used endoscopically, and may also be used innon-endoscopic procedures, and provides both stapling and cutting to thesurgical site. It is desired to have tissue clamped between the jaws ofthe stapling mechanism, and it is also desired that the staplingmechanism accomplish this clamping and then firing in a two-part,sequenced operation.

It is further an object to provide a stapling and clamping mechanismwhereby the clamping mechanism causes the stapling mechanism to be putinto position for firing.

This novel concept also necessarily requires that one is prevented fromactuating the firing mechanism before clamping is accomplished.Therefore, it is further an object to prevent firing of the staplingmechanism before the entire clamping procedure is completed or if acartridge is missing or has been previously fired.

It is further an object to provide a rotational mechanism whichaccommodates stapling and cutting endoscopically.

It is further an object to provide a closure mechanism so than theclosure mechanism is not able to inadvertently spring open before thefiring mechanism has been fully actuated. It is yet another object toprovide a mechanism which allows forward and reverse motion of aclamping trigger such that forward motion causes clamping, and thenpermits stapling, and reverse motion permits the jaws of the mechanismto be opened, by reversing the functions of the clamping mechanism.

Yet another object is to provide a mechanism for remotely articulatingthe clamping and stapling portion of the instrument, before, during,and/or after completion of the surgical procedure.

It is an object to provide a closure mechanism in a surgical staplerwhich accomplishes clamping of the tissue to be stapled in a directionopposite that of stapling, that is, from the distal toward the proximalend of the stapler. In this way, proper amounts of tissue may beadequately clamped, and then stapled.

It is yet another object of the invention to provide a safety featurefor retracting or otherwise shielding the knife of the instrument fromthe patient and operator prior to and/or following the cutting sequence.It is a further object of the invention to provide an instrument whichcan cut and staple in an axis which is not colinear with the shaft, toprovide a self-contained cartridge/wedge assembly to be used inconjunction with the handle, to provide lower cost materials ofconstruction, such as plastic, for use in wedges for only one firing,and to keep the head length of the cartridge to a minimum.

It is a further object of the invention to provide a disposablecartridge assembly which completely encases the firing wedges and knife,such that the knife and wedges do not return to their start positions atthe end of a firing sequence.

It is another object of the invention to provide an improved device forlocking the head of an articulating surgical instrument.

Finally, it is an object of the invention to provide an improvedarticulation connection comprising a flexible neck, allowing for arelatively large bend radius and consequent smooth transmission offorces around the bend.

These and other objects of the invention are described in an improvedsurgical instrument, such as an endoscopic stapling mechanism which iscapable of clamping, stapling and cutting tissue. The stapling mechanismutilizes a surgical stapling cartridge which contains at least twodouble rows of staples. The stapling cartridge also provides for knifemeans to divide the two double rows of staples during the staplingfunction. The stapling mechanism contains a trigger mechanism whichcontains a double trigger feature. One of the triggers causes clampingof tissue. The other trigger causes firing staples and actuation of theknife. Thus, clamping and firing are accomplished separately. Becausethe system contains a safety mechanism, there cannot be firing ofstaples before there is full clamping of tissue. In this mechanism,stapling is accomplished in any rotatable position, as soon as tissuehas been clamped. Yet, the clamping trigger locks in position so that itwill not inadvertently spring open during use of the firing trigger.

In one of the embodiments described herein, there is contained in theendoscopic stapling mechanism a double clutch mechanism which allows theuser to derive benefits from both forward and reverse motion of theclamping and firing triggers. During forward motion of the triggers,there is clamping and then firing. During reverse motion, there is thecapability of overriding any jams encountered by the stapling mechanism,and then allowing the stapled tissue to be removed from the staplingsite.

Furthermore, in this invention there is the capability of having distalclamping of tissue, wherein relatively larger tissue is held within alarger size device. After this clamping, there is then proximal contactof the stapling and closure means and thereafter, similar proximalcontact of the knife mechanism. Thus, while it is easily ascertainablehow much tissue is clamped between the clamping mechanisms, it is alsoeasy to determine whether clamping and stapling have been properlyaccomplished.

In a highly preferred embodiment of the invention, a mechanism forremotely articulating the stapling and clamping portion of the surgicalinstrument is provided, including an articulating coupling device, whichmy be, for example, a ball-in-socket type coupling, a knuckle joint, aflexible neck, a flexible band or strap, a hinge and pin coupling, arack and pinion, or other coupling device. In a most highly preferredembodiment, a joy stick mounted proximately to the handle allowsrotational motion of the joy stick to be translated into articulationalmotion of the stapling and clamping portion about the aforementionedarticulating coupling.

In another highly preferred embodiment of the invention, the knifemechanism retracts within the staple cartridge at the completion of thecutting sequence, and in a most highly preferred embodiment, separatesfrom the knife/wedge driver and is retained, retracted, in the staplecartridge, which is removed and disposed of, to be replaced by a newstaple cartridge having a new knife, which may be driven by the sameknife/wedge that remains in the instrument.

In yet another highly preferred embodiment of the invention, an improvedlocking mechanism for redirecting or eliminating deflection in the headof articulating surgical instruments is provided. The locking mechanismmay be independently controlled with respect to the articulatingmechanism, or operationally connected to the articulating mechanism. Thelocking mechanism locks the head of the assembly in an articulatedposition whenever the articulation control is not being used. That is,the articulation lock is generally engaged, disengages when thearticulation control is being used, thereby allowing articulation of thehead, and relocks the head in its new articulated position when thearticulation step is completed.

Finally, in yet another, highly preferred embodiment of the invention, aflexible neck connection is provided for articulating a surgical headassembly with respect to a rigid shaft to which the head assembly ismounted. The flexible neck may be a flexible material with a pluralityof ribs therein, which may be articulated with push/pull techniques, ormay comprise a pre-articulated neck that assumes a curve as it isadvanced through a linear shaft.

These and other objects of the invention will be better understood fromthe following attached Detailed Description of the Drawings, when takenin conjunction with the Detailed Description of the Invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of an endoscopic linear stapling andcutting mechanism of the present invention;

FIG. 1a is an exploded perspective view of the instrument of FIG. 1;

FIGS. 2a and 2b are cross-sectional views of the view of FIG. 1;

FIGS. 3 and 3a are individual and closeup views of the closure triggerof the present invention;

FIGS. 4 and 7 are operational views of the closure trigger and togglelinkage of the invention;

FIGS. 5 and 6 are isolated side and top views of the firing trigger ofthe invention;

FIGS. 8 and 8a are side and bottom isolated views of a typical cartridgeof the invention;

FIGS. 9 and 9a are side and bottom isolated views of the anvil of theinvention;

FIGS. 9b, 9c and 9d are side operational views of the interactionbetween the stapler shaft, the cartridge, and the anvil closingmechanism;

FIG. 10 is a side isolated view of the knife means with a lockout notch;

FIG. 10a is a side view of an alternate knife means with no lockoutnotch;

FIG. 11 is a side isolated view of the lockout member contained in thecartridge of FIGS. 8 and 8a.

FIGS. 11a and 11b show the motion of the lockout member of FIG. 11 whenmoved by the knife means of FIG. 10 in the cartridge of FIG. 8;

FIG. 12 is a side elevational view of an alternate preferred embodimentof the stapler of the present invention;

FIG. 12a is an exploded perspective view of the instrument of FIG. 12

FIG. 13 is a cross-sectional view of the stapler of FIG. 12;

FIG. 14 is a side view of the closing trigger plate of the embodiment asdescribed in FIGS. 12 and 13;

FIG. 15 is a side view of the firing trigger as seen in FIG. 13 of thepresent invention;

FIG. 15a is a side view of the trigger return linkage of the alternateembodiment of this invention;

FIGS. 16 and 16a are isolated views of the front toggle link as seen inFIG. 13 of the present invention;

FIGS. 17 and 17a are isolated plan views of the rear toggle link as alsodescribed in FIG. 13 of the present invention;

FIGS. 18 and 18a are isolated side and top views of another typicalcartridge, as used in the stapler of FIG. 12;

FIGS. 19 and 19a are isolated side and bottom views of the anvil memberused in the stapler of FIG. 12;

FIG. 20 is a detailed view of the knife mechanism and lockout notch asused in the cartridge of FIG. 18, as seen in the views of FIGS. 12 and13 describing the 15 alternate embodiment of the present invention; and

FIGS. 20a and 20b are views of the lockout mechanism before and aftermotion of the knife means of FIGS. 19 as in the stapler of FIGS. 12 and13.

FIGS. 21a and 21b are sectional views of a preferred staple cartridge ofthe invention, showing the retractable knife in its retracted "start"position in FIG. 21a, and its retracted end position in FIG. 21b.

FIG. 22 is an isometric view of a preferred cartridge of the presentinvention.

FIG. 23 is a cross-sectional view of a preferred staple cartridge of theinvention, showing the retractable knife in its cutting position.

FIG. 24 is an isometric view of a knife/wedge decoupling assembly foruse in a preferred embodiment of the invention.

FIG. 25 is a cross sectional view illustrating a knife decoupled from awedge in a preferred embodiment of the invention.

FIG. 26 is an isometric view, partially broken away, of a preferredarticulation locking device of the present invention.

FIG. 27 is an overhead view of another preferred articulation lockingdevice of the present invention.

FIG. 28A is an isometric view of another preferred articulation lockingdevice of the present invention.

FIG. 28B is a top plan view of the device of FIG. 28A.

FIG. 29 is an isometric, exploded view of another preferred articulationlocking device of the present invention.

FIG. 29A is a top plan view of the distal end of the device of FIG. 29,showing the head in a locked unarticulated position.

FIG. 29B is a top plan view of the distal end of the device of FIG. 29,showing the head in an articulated position, and the locking device inan unlocked position.

FIG. 29C is a top plan view of the distal end of the devices of FIG. 29,showing the head in a locked articulated position.

FIG. 30 is a top plan view, partially broken away, of another preferredarticulation locking device of the present invention, illustrated in anunarticulated mode.

FIG. 30A is a close up view of a portion of the device of FIG. 30,showing the locking device in greater detail.

FIG. 31 is a top plan view of the device of FIG. 30, illustrating thelocking device in an articulated mode.

FIGS. 31A and 31B are schematic representations of the "valving"function performed by the locking device of FIGS. 30 and 31.

FIGS. 32A and 32B are schematic illustrations of a preferred anvilclosure mechanism of the present invention having a closure tube.

FIG. 33 is an isomeric view of a preferred anvil closure mechanism ofthe invention having a closure tube.

FIGS. 34A and 34B are schematic illustrations of a wedge anvil closuremechanism of the present invention in the open and closed position,respectively.

FIG. 34C is a schematic illustration of another wedge anvil closuremechanism of the present invention.

FIG. 35 is an exploded isometric view of another anvil closure mechanismof the present invention.

FIG. 35A is an end elevation view of the anvil of FIG. 35.

FIG. 36 is a cross-sectional top plan view of a preferred embodiment ofa flexible neck of the present invention.

FIG. 36a is a schematic illustration of a variable bend radius flexibleneck of the present invention.

FIG. 37 is a cross-sectional view, taken along lines 37--37 of FIG. 36,rotated 90°, of a preferred flexible neck of the invention.

FIG. 38 is a side elevational view of the top half of the flexible neckof FIG. 37.

FIG. 39 is a bottom plan view of another preferred embodiment of aflexible neck of the present invention having a "herringbone" shapedseries of kerfs.

FIG. 40 is a side elevation of the flexible neck of FIG. 39.

FIG. 41 is a left side view along lines 41--41 of FIG. 40.

FIG. 42 is an isometric view of the distal portion of a preferredsurgical instrument of the invention.

FIG. 43A--43C are a series of tools and mechanisms that may be slidablyreceived by the flexible member of the instrument of FIG. 42.

FIG. 44 is a cross-sectional view of another preferred flexible memberof the present invention.

FIG. 44A is a cross-sectional view of the flexible member of FIG. 44taken along lines A--A.

FIG. 45 is an elevational view of another flexible member of the presentinvention, shown in a flexed orientation.

FIG. 46 is an elevational view of a flexible member of the presentinvention shown in a straight orientation.

FIG. 47 is an elevational view of an outer tube used to straightenand/or cause the curvature of the flexible members of FIGS. 45 and 46.

FIG. 48 is an isometric exploded view of the flexible member of FIG. 46.

FIG. 49 is an elevational, cross sectional view of the flexible memberof FIG. 48.

FIG. 49A is a cross sectional view taken along lines A--A of theembodiment Illustrated in FIG. 49.

FIG. 49B is a cross sectional view taken along lines B--B of theembodiment of FIG. 49.

FIG. 50 is a cross sectional view of another preferred flexible memberof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As can be seen from FIGS. 1, 1a, and 2 in one embodiment of the surgicalstapler of this invention, there is described a stapler 100 whichcontains a handle portion 110, rotating means 120, a shaft portion 130,anvil portion 140, and cartridge assembly 150. A knife means 160 isslidable within the cartridge assembly 150 to cut tissue. In the handleportion 110 there is a first or closure trigger (also called a clampingtrigger) 112, and second or firing trigger 114. The clamping trigger 112causes the anvil portion 140 to come into proximity of the cartridgeassembly 150. The firing trigger 114 causes the wedges 122 located inthe shaft 130 to move through the cartridge assembly 150, and alsocauses the knife means 160, also located in the shaft 130 to movethrough the cartridge assembly 150, in order to cut tissue.

As can be seen in more detail in FIGS. 1a, 12a, 2b, 3, 4, 5, 6 and 7 theendoscopic linear stapling mechanism 100 contains a double triggermechanism. The first or clamping trigger 112 is for closing the jaws132, 142 of the instrument onto tissue, and the second or firing trigger114 is used for firing the stapler 100. The intent of the double triggerdesign is to combine one-handed use within a stapling mechanism, and tomake such one-handed use so that it is impossible to form staples unlessthe instrument is fully closed.

When the instrument is initially loaded, with cartridge assembly 150held within shaft portion 130 on jaw 132, the firing trigger 114 isflush with the body 116 of the instrument, so that it is parallel withthe shaft portion 130, and is for all practical purposes inaccessible tothe user. During actuation of the clamping trigger 112, the firingtrigger 114 swings into a "ready" position preparatory to actuation.This position is 35° to 45° spaced apart from the closure trigger 112,which has now moved into position against base 118. As will be laterdescribed, a multiplier mechanism causes the firing trigger 114 to movethrough a greater arc than closure trigger 112.

The closure trigger is spring-loaded, so that an incomplete closureresults in the closure trigger swinging open to its position as seen inFIGS. 1 and 2, once again spacing the staple firing trigger 114 awayfrom the reach of the hand operating the mechanism. A closure sequencemust therefore be completed, with the clamping trigger 112 lockingproximal to the base 118, before the firing trigger 114 can be graspedor is operational by the user.

As can be seen from the FIGS. 1a, 2, 3, 3a, 4 and 7, the closure trigger112 is attached to a front closure link 124, at pivot pin 126. Closuretrigger 112 is also attached to a rear closure link 128 which pivotsinside the handle 110 of the stapler 100. The closure trigger 112therefore is capable of pivoting around the handle portion at pivot 113,so that it moves roughly 25°-50°, in this instance, preferably 35°. Theclosure trigger 112 is spring-loaded at spring 129 so that unless theclosure trigger 112 is fully rotated toward the base 118, the spring 129causes the closure trigger 112 to reopen to its initial position. Aswill be later explained, it is the motion of this closure trigger 112which causes the anvil portion 140 to clamp into proximity of cartridgeassembly 150.

Furthermore, the closure trigger 112 is connected by means of a pin tothe firing trigger 114. Thus, as can be best seen in FIGS. 2b, 3, 5 and6, the closure trigger 112 is linked with the firing trigger 114 bymeans of a pin 119 which moves in a guided path along slot 117 away fromthe axis of rotation of the closure trigger 112. This pin 119, in turn,moves along a path within slot 117 of the firing trigger 114. As betterseen in FIGS. 2b, 5, 6 and 7, the rotation of the closure trigger forapproximately 35° results in rotation of the firing trigger forapproximately 45°. The control of the pin 119 is accomplished by guideplates placed in the body 116 of handle portion 110. Now, closuretrigger 112 is in place at the base 118 of handle 116. Firing trigger114 needs to travel only 30°-60° to complete a full firing stroke. Thisarc is quite manageable for even the smallest human hands.

After its initial rotation, this guiding pin no longer acts upon thefiring trigger 114. That is, this guide pin 119 is no longer in contactwith the firing trigger 114. This allows the firing trigger 114 tocomplete its rotation and fire staples without interaction of guide pin119 or with the closure trigger 112. Thereby, the firing trigger 114 isconnected to a spring 121 as seen in FIG. 1, which is in turn connectedto the handle 110. This spring causes the firing trigger 114 to returnto the 45° position so that triggers 112, 114 may be returned duringopening of the instrument 100.

As can be seen in FIGS. 1, 1a and 2b, and especially in FIG. 4, there iscontained a locking mechanism comprising button 131 which activates leafspring involution 159a on leaf spring 159, in order to cause the closuretrigger 112 to be locked once it reaches base 118 of the handle 116. Theclosure trigger 112 is locked in place by leaf spring 159 which seatsunder frame closure link 124 thus immobilizing pin 126. This in turnrestrains closure trigger 112. The safety button 131 is pivotallymounted to the proximal top of base 118 and rests upon leaf spring 159.As will later be explained, 30 thereafter, the firing trigger 114 isfree to move alone.

As further can be seen from FIGS. 2b, 4 and 7, motion of closure trigger112 causes motion of front and rear closure links 124, 128. These frontand rear closure links 124, 128 cause motion in line with the shaft 130of a closure sliding member 136. This closure sliding member 136 isattached in a rotatable fashion at joint 135. On the distal side ofjoint 135 is closure coupler 134, which attaches to the end of a closurechannel 138. It is the closure channel 138 which is attached to the pin139 in the shaft 130 that connects this mechanism to anvil 140.

Closure channel 138 causes closure of the anvil portion 140 intoproximity and alignment with the cartridge assembly 150. This isaccomplished in that the closure links 124, 128 first move parallel tothe axis of the shaft 130, as in FIG. 7, from their original positionsin FIG. 4. Closure channel 138 is caused to slide within shaft 130. Thefront top surface 138a of closure channel 138 pushes forward and down onthe anvil. This causes anvil 140 to come parallel to cartridge assembly150 so that there is alignment of cartridge 150 and anvil 140. The shaft130 is formed from a stationary tube, so that the closure channel 138moves within the stationary tube 131 of shaft 130 at the distal end ofthe instrument 100.

This double trigger mechanism 112, 114 has the following advantages. Thefiring trigger 112 cannot be actuated until the closure trigger 114 hasbeen completely snapped into its final position, due to locking of theclosure trigger 112 inside the handle 110. Therefore, one is certainthat tissue has been clamped before the firing trigger 114 has beenplaced into motion. The firing trigger 114 can be actuated withoutrepositioning the hand following closure of the instrument. Than is, thehand stays stationary, and is once again gripped around the firingtrigger 114, with closure trigger 112 maintained at the base 118 of thehandle 110. This facilitates rapid completion of the firing sequencewithout requiring the surgeon's attention on the stapler away from theendoscopic video screen and thereby away from the operating arena. Inaddition, both the closure trigger 112 and the firing trigger 114utilize a mechanism which is familiar to those who use surgicalinstruments, a pistol grip with a trigger type actuation.

As has earlier been explained, the closure trigger 112 pushes on thecentral pivot pin 126 of a toggle linkage 124, 128. Central pivot pin126 rides in slot 115. This central pivot pin 126 results in relativelylarge amounts of motion in the closure channel 138 (see FIG. 4) whichresults in gross closure of the instrument 100. The mechanical advantageprovided by the toggle linkage 124, 128 during this portion of closureis relatively small. This has the advantage of providing the user withhigh tactile feedback. That is, the user is readily able to tell whetherthe system is overloaded with tissue. Near the position wherein movementof the toggle linkage 124, 128, (FIG. 7) is nearly complete, the closuretrigger 112 has moved into place at base 118, and front closure link 124and rear closure link 128 have been made generally parallel to the shaft130, relatively little motion of the linkage 124, 128 results from anygiven rotation of the trigger 112. Trigger 112 rotation at this pointprovides significantly higher closure force than during the firstportion of its motion. This is critical in accomplishing preloading ofanvil 140 during the final portion of closure, and is in theory onlyconstrained by the structural limitations of the system.

As can be seen from FIGS. 2b, 5 and 6, firing is accomplished by asimple rotation of the firing trigger 114 acting as a lever arm aboutpivot 113. The firing trigger is linked to the firing or driver rod 144and driver rod link 146 by means of firing links 148. These firing linksare engaged with the firing triggers by means of a clutch. This clutchmechanism is better seen in the top view of the firing trigger as seenin FIG. 6.

This clutch mechanism does not engage the firing link 148 until thefiring trigger 114 is in a "ready to fire" position, whereby hook 149engages link 148. This eliminates the potential for firing theinstrument prior to complete closure of the mechanism by closure trigger112.

Once the clutch system has engaged the firing link 148, this causes thedriver rod link 146 to be translated by pin 145, and moving with link148 in slot 147, in a generally parallel position to the shaft 130 ofthe mechanism. This driver rod link 146 is connected to driver rod 144which is rotatably connected in nozzle 120 to a pusher block 152contained in the shaft 130. This pusher block is connected to firingwedges 122 and knife mechanism 160, as seen at the proximal edge of theshaft 130 which enters the cartridge assembly 150. The firing wedges 122are able to transversely move staples loaded in the cartridge assembly150 so that they are fired into the anvil portion 140, as best seen inFIGS. 2a, 8, 8a, 9 and 9a, and as well known in the art. The knifemechanism 160 is capable of cutting tissue between the completed pair ofdouble or triple rows(or more) of staples, as also is well known in theare.

After firing has been completed, the firing mechanism returns by meansof a compression spring 156 placed about driver rod 144 along shaft 130,so than spring 156 is stationary at base 157, which causes the driverrod 144 to be moved in a direction reverse from firing. Spring 156itself has a sufficient strength to also cause driver rod 144 to movethe firing link 148 via linkage 146 to return to its ready to fireposition. This similarly causes the driver rod 144 to pull the wedges122 and the knife 160 so that they are removed from the cartridgeassembly 150. If the wedges 122 or the knife 160 do not return, that isif they are jammed, the firing mechanism comprising the firing trigger114 contains a reverse clutch assembly which allows the firing trigger114 to engage with the firing link 148 at hook 151 (FIG. 6) so that itis capable of causing this assembly to move in a reverse or rearwarddirection. This provides a backup to the system, in the event there is afailure in the driver return spring 156 or if the instrument hasinadvertently been misassembled.

The system also contains a safety mechanism which locks the closuretrigger 112 in its closed position. This safety mechanism is a leafspring 159 which interacts with the safety button 131 on the rear of theinstrument. Side plates on the portion of the toggle linkage assembly124, 126 cause the leaf spring to remain in a tensioned position, andguide the leaf spring during its motion. When the front closure link 124is in its straightened position, so that the rear closure link 128 isalso rotated to be generally parallel with the shaft 130, the leafspring 159 has been tensioned to restrain the toggle linkage 124, 128 inits parallel position. The safety button 131 on the rear of theinstrument thereafter urges the leaf spring 159 in a forward direction,toward the cutting mechanism. This forward motion of the spring 159causes the toggle linkages 124, 128 to be freed from the restraint ofthe spring 159. This motion allows freedom of movement for closuretrigger 112.

As has been previously described, and as better seen in FIGS. 2a, 8, 9and 9a-9d, the jaws 132, 142 of this instrument are closed by means of acam surface 127 on the outer surface of the anvil 140. The anvil 140pivots about pin 139 embedded in slot 141 of the closure channel 138 inshaft 130. Channel 138 is pushed forward with the actuation of theclosure trigger 112. Closure channel surface 138a bears upon the camsurface 127 of the anvil 140, forcing it to pivot and move transverselywithin slot 153 contained in shaft 130. The location of the slot 153 ascompared to the surface profile of the cam 127 determines motion of theanvil 140, such that the slot 153 and slot 141 combination forms a"fixed" pivot, which is fixed only with respect to the anvil 140.Therefore, anvil 140 is allowed to move transversely across the axis ofa stationary tube 130. Shaft or stationary tube 130 forms the "ground"position for the pivot pin 139, so that its motion is only transversecompared to the shaft 130. As better seen in FIGS. 9b-9d, the motion ofthe anvil 140 follows a predetermined path. First, the anvil 140 isrotated to a position parallel to cartridge 150. Then, anvil 140 movesin a direction transverse to the axis of shaft 130, maintaining itsparallel alignment with cartridge 150, until it is abutting pin 161 oncartridge 150.

This mechanism is also assisted by surface 127b on the opposite side ofanvil 140. This is better seen in FIG. 9. This second cam surface 127bon the opposite portion of the proximal end of anvil 140 rides onbuttons 139b held within the closure channel 138 during opening of theinstrument. Second cam surface 127b similarly causes a reverse, openingmotion of anvil 140 upon of closure trigger 112 au the opening of theinstrument.

The anvil 140 comes to rest on the gap spacing pin 161 which forms thedistal end of the cartridge 150. The gap spacing pin 161 causes theanvil 140 to be held roughly parallel to the cartridge 150. This has anadvantage in providing an evenly spaced tissue compression. It also hasan advantage of retaining tissue between the anvil 140 and the cartridgeassembly 150 and keeps the tissue from being "oozed" out of the distalend of the instrument 100. In this way, the anvil 140 acts as a simplysupported beam with an evenly distributed load. As better seen in FIGS.8 and 8a, there is provided a cartridge assembly containing six rows 190of staples. These staples are arranged with two pairs of pusher blocks192 near the outside of the cartridge 150. Then, one pair of pusherblocks 194 is placed within the interior of cartridge 150. Thus, fourwedges 122 pass through this cartridge 150, as better seen in FIG. 8a.Of course, knife 160 also passes through the center of cartridge 150.

The firing force to form the staples provides an additionalconcentrated, yet moving, load on the cantilever beam which forms theanvil 140. The tissue compression load and the staple forming forcestend to deflect the anvil 140 from the cartridge 150. The anviltherefore is preloaded, so that uneven staple forming is avoided. Thispreload is placed on the gap spacing pin 161 at the end of the cartridge150 so that a load roughly equivalent to that of tissue compressionforce and staple forming force is countered. This makes the anvil 140acts simply supported beam, with loads an each end. This preload meansthat the anvil deflection caused by tissue compression and stapleformation is compensated for by the reverse deflection caused by the gapspacing pin 161.

The disclosures of U.S. Pat. Nos. 4,633,861 and 4,633,874 (Chow, et al.)are incorporated by reference.

it can be seen in FIGS. 8, 11, 11a and 11b, that there is a uniquelockout feature to this embodiment. As seen FIGS. 11a and 11b, thecartridge 150 contains a lockout member 170, having raised members 170a,which is better seen in FIG. 11. This lockout member 170 is providedwithin the cartridge so that is serves to lift the knife blade 160 overan obstructional block 172 placed within the stationary tube 130 of themechanism. This causes the obstruction 172 to be cleared by the knife160. Then, the knife 160 proceeds through the cartridge 150 for cutting.However, the knife has a notch 162 which engages the lockout member 170,arid pushes it into opening 165 of cartridge 150. In this way, thelockout mechanism 170 operates at an even earlier time frame thanpreviously disclosed locking mechanisms. It is important to realize thatwith the lockout mechanism described herein, the knife 160 is blockedeven before entrance into cartridge 150.

As seen in FIG. 11b, after the knife 160 has been inserted into thecartridge 150, the raised members 170a of lockout member 170 have beencaused to be captured below its cartridge retaining member 164 inopening 165, so that lockout member 170 becomes locked permanentlywithin the cartridge 150. Therefore, after the knife 160 is retractedinto the shaft 130, obstruction 172 now is level with the notch 166. Inthis way, there is no longer any clearance, between notch 166 andobstruction 172, as seen in FIG. 11b. In this way, if it is desired torefire this stapler, there is no possibility of knife hook 166 clearingthe knife obstruction 172 in shaft 130. Therefore, refiring of thisspent cartridge 150 is not possible.

If one were willing to accept any disadvantages which may be attendant,the stapler 100 may be modified as seen in FIG. 10a to allow cuttingafter the last staple has been fired. This is accomplished by removingmember 166a adjacent to notch 166 using conventional methods, forexample grinding or cutting. Or, knife 160 may be manufactured withoutnotch 166 and member 166a.

Therefore, as seen from all the Figures previously listed above taken inconjunction with this Description, the following is a summary of theoperation of the present invention. A fully loaded cartridge 150 isinserted into the stationary tube 130 at jaw 132. Thereafter, theinstrument is inserted, closed, within a trocar and is opened, andgathers tissue between the anvil 140 and the cartridge assembly 150. Theclosure channel is operated by compressing the closure trigger 112. Inthis way, the closure trigger 112 causes all the closure mechanisms torotate and move along an axis parallel to shaft 130. This causes theanvil 140 to encounter the gap setting pin 161 and capture tissuebetween the anvil 140 and cartridge 150. Thereafter, the anvil 140 iscompressed onto the cartridge 150.

In the meantime, the clutch assembly of the firing trigger 114 hasengaged the firing link 148, which is now operated. Tissue is stapled byrotation of the trigger 114. Also, simultaneously, the tissue is cut bythe knife member 160. Once the firing stroke of the firing trigger 114is completed, the rear safety button 131 must be released so that themechanism can be reopened. The firing trigger 114 and closure trigger112 are rotated to their original positions, and the lockout member 270has caused the knife 160 to be obstructed from refiring. Thus the tissueis released, the mechanism retracted from the trocar tube, the cartridge150 removed and a new cartridge inserted, and the stapler is again readyfor firing.

As seen in FIGS. 12 through 20a, there is described an alternativepreferred embodiment of the present invention. There is seen a staplerwhich contains a handle portion 10, shaft portion 30, an anvil portion40, cartridge assembly 50, rotational means 20, a first or closingtrigger 12, a second or firing trigger 14, knife means 60, and firingwedges 54. The basic functions of all of these subassemblies are quitesimilar to those as described in the first preferred embodiment.However, there are certain aspects of the system which will now be moreparticularly described.

As seen in FIGS. 12 and 13, there is described a closure sheath 32 whichis capable of camming the rear cam surface 43 of the anvil 40. Thisclosure sheath 32 is operated by means of the closing trigger 12,attached thereto by means of a closure mechanism. The firing trigger 14is similar to firing trigger 114 of the first embodiment, and is capableof activating the firing wedges 54 to expel staples from the staplingcartridge, while simultaneously activating knife means 60 to cut tissuebetween the two double rows of staples contained in cartridge assembly50.

As will be better understood, there are certain aspects of the handlemechanism 10 which differ from the handle mechanism 110 of the firstembodiment. As better seen in FIGS. 12a, 13, 14, 15 and 15a, the closingtrigger 12 which operates the sheath 32 of the stapler is connected tofiring trigger 14 by means of a two-piece linkage 34, 36. This linkagesystem 34, 36, is better seen in FIGS. 12a and 15a. Link 34 is connectedby means of a pivot joint 45 to firing trigger 14 and is constrained totravel within an opening 45a in firing trigger 14. Link 34 is biaseddownward by spring means 33 connecting it to a boss in body plate 155.Link 36 is connected by means of a pivot joint 46 to closing trigger 12and is constrained to travel within an opening 46a in trigger 12. Links34 and 36 are constrained to move relative to each other due to link 36nesting inside of a slot in link 34. The distance from pivot pin 13 topivot joint 45 at which link 34 is connected to firing trigger 14 isproportionately smaller than that at which link 36 is connected toclosing trigger 12. These differing distances or radii from pivot pin 13cause the firing trigger 14 to rotate through a greater angle than thatof the closing trigger 12 when the closing trigger mechanism isactivated. This allows the firing trigger 14 to move from its initialposition against the barrel position of the body to a position in whichit can be easily activated for the firing operation. This occurs becauselink 36 is pulled upwards by the closing trigger 12 and, since it isnested in the slot 37 in link 36, link 34 pulls link 36 upward as well.The firing trigger 14 can be rotated into position against the gripportion of handle and continues to raise link 36. This additional travelof link 36 is accomplished since the slot in link longer than the bodylength of link 36 which is engaged in the slot 37. Spring means 33connected to link 34 causes link 34 to remain in contact with link 36 aswell as to help return both links 34 and 36 and the respective triggers12 and 14 to their original positions.

As seen in FIGS. 13, 16 16a, 17 and 17a, rear toggle member 44 has anextended portion 47 which rotates into a 15 position so that in contactsthe rear button release 31. The front toggle member 42, and rear togglemember 44 form the toggle linkage and are cammed into an over-centerposition, thus locking sheath 32 into a position which cams anvil 40against cartridge assembly 50. Pushing the rear button release 31 exertsforce on the elongated part 47 of the rear toggle 44 and rotates therear toggle 44 past its over-center point. This allows spring 150a inconjunction with spring 33 and the linkage 34, 36 to pull the firingtrigger 14, and closing trigger 12 into the "ready" position. Of course,both links 34, 36 of the trigger return act respectively on the triggers14, 12. In this way, the stapler 5 is reset for firing as seen in FIG.13.

As also seen,in FIGS. 12a and 13, there is contained in this mechanism asafety pawl. The safety pawl 22 is capable of preventing motion of thefiring mechanism of this embodiment of stapler 5 until closing trigger12 has been fully moved to its closed position against the instrumenthand grip 18 of handle portion 10. Safety pawl 22 is biased into itsblocking position by means of spring 160a. Safety pawl 22 is moved outof the way of the firing mechanism through contact of latch 42a withnotch 5 22a. That is, the safety pawl 22 becomes disengaged from itsblocking position against the firing rack 25 which ultimately isoperated by the firing trigger 14. Once the safety panel 22 has beenmoved, firing can take place. As better seen in FIGS. 12, 13, 16, 16a,17 and 17a, closure is initiated by moving the closing trigger 12against the instrument handle grip 18. This rotates the toggle linkageto its locked and over-center point, that is generally parallel withstapler shaft 30. This further causes sheath 32 to move in place withinthe stationary channel 30a which forms the shaft portion 30 of themechanism. Thus, the toggle linkage which comprises both the rear toggle44 and the front toggle 42, operates so that it moves the closure sheath32 (which may operate as a cramming collar) over the base 43 of theanvil 40. Thus, the closure mechanism now causes the anvil 40 andcartridge 50 to come in close proximity to each other.

At that point, the closure trigger 12 is held against the hand grip 18and the firing trigger 14 is ready for actuation. The firing trigger 14operates driver 89 connected to a belt 17, which is used to providemovement of firing rack 25 and driver rod 19. The belt 17 acts as amultiplier mechanism so than the firing trigger 14 pushes against thedriver 89, seen in FIG. 13. Driver 89 thereafter causes the bottomportion 17c of belt 17 to move forward. Because one end of the belt 17ais fixed against the body of handle 18 off, the stapler 5, and the otherend of the belt 17b is attached to rack 25, this drives the knife means60 and wedges 54 of the stapling mechanism forward. The motion of belt17 causes motion of the driving rod 19 to be amplified as against therotational motion of the firing trigger 14. Thus, this belt mechanismmultiplies the firing distance travelled, so that stapling and cuttingcan take place.

The anvil portion 40 and cartridge assembly 50 operate very much as thatof the first preferred embodiment. One difference, however, is that apreload is accomplished by tilting the anvil 40 and cartridge 50 towardeach other at their distal ends to force distal closure to occur. As theproximal ends 40a of the anvil 40 and cartridge 50 are brought into aparallel position a preload is placed on 15 the gap pin 61. This isbetter seen in FIGS. 13 and 18. The cam mechanism 43 on the rear of theanvil 40 is designed with a multiple angle. In this way, the steeperproximal portion of the angle allows faster closing of the anvil 40against the cartridge assembly 50. Then the distal or more shallow angleis contacted by the closing sheath 32 when the instrument is nearlyclosed and experiencing high tissue load and high preload on the gapsetting pin 61 found in the forward most position of the cartridge 50.These compound angles are specifically designed to give highermechanical advantage when needed and faster closure and wider openingwhen needed.

As better seen in FIGS. 18, 18a, 19, 19a, 20, 20a and 20b, the lockoutmechanism of the second embodiment is 30 better seen when examining thecartridge 50 of the present system. There, it is seen as in FIG. 20, thelockout tab 71 is originally provided so that it is capable of liftingthe knife means 60. In this way, the knife 60 moves forward and into thestapling cartridge 50. On the rearward motion of the knife, theforwardmost edge 63 of the knife mechanism 60 causes the lockout tab 71to be rotated to become parallel with the stapling shaft 30. Thus, theknife 60 is made to move to a position lower in the stapling shaft 30.This causes the channel hook 59a which is contained in the staplingchannel 59 to come into contact with the space 65 formed within theknife means 60. Thus, when it is now desired to move the knife mechanismforward, as will readily be appreciated, the hook 59 now catches onforward facing lip 66 of the knife means 60. Thus, the knife isincapable of moving forward and the stapler is now locked from firingthrough an already spent cartridge 50.

Of course, as seen in FIGS. 18 and 18a, there are disclosed four rows,that is two double rows 92 of staples in the cartridge 50. These rows 92are actuated by pusher blocks 94 contacting wedges 54. Knife 60 passesthrough the center of rows 92.

In operation, the stapler of this second embodiment also performssimilar functions. There is similar stapler safety, and clamping as thatof the first preferred embodiment, and the firing and cutting of tissue25 accomplished all in the same order. Stapler lockout is accomplishedafterwards by retraction of the knife mechanism.

In a most highly preferred embodiment of the invention, a retractableknife is provided, eliminating the need for a spent cartridge lockout.Referring now to FIGS. 21-23, a housing, generally 200 contains one ormore staple drivers generally 202 which form staples 204 substantiallyas previously described. The housing 200 also contains a wedge/knifesled subassembly, generally 201, comprising a knife or knife sled 206and a wedge or wedge sled (containing multiple wedges) 208. The knife206 is pivotally mounted to the wedge sled 208 via a pin 210, the pivotpin 210 riding within an inclined slot 212 in the knife 206. The pivotpin 210 also passes through an opening 214 in each of the wedges of thewedge sled 208. The wedge/knife sled subassembly 201 is retained withinthe housing or cartridge 200 by a driver retainer 216.

A pusher 218 emanating from the handle of the instrument urges thewedge/knife sled assembly, generally 201, in the direction D₁, whenactuated by the operator of the instrument. As the wedges 208 are pushedin the direction D₁ by the pusher or driver rod 218, the front inclinededge 209 of the wedge contacts a complimentary inclined edge 203 of thestaple driver(s) 202, forcing the staple driver(s) in the direction D₂,firing the staples through the tissue and forming them about an anvil(not shown) substantially as previously described. This staple firingsequence occurs following the clamping of the tissue between thecartridge 200 and the anvil as previously described.

Referring now to FIG. 21a, the sled assembly 201 is initially positionedat the rear 205 of the housing 200. As further illustrated in FIG. 21a,in this "start" position, the knife 206, by virtue of the pivot pin 210and a slot 217 in the rear of driver retainer 216 (see also FIG. 23), isinitially positioned with the tip of the knife 206 being below theexposed surface 207 of the cartridge 200. In this unexposed position,the knife 206 is incapable of inadvertently cutting the operator orpatient.

During operation, at the initiation of a firing/cutting sequence, thepusher or driver rod 218 is advanced in the direction D₁, for example,by actuating a trigger mechanism at the handle of the instrumentsubstantially as previously described. Alternatively, the pushermechanism 218 could be manually advanced, although this would be a lesspreferred embodiment. The pusher 218 slides within a channel 219 withinthe cartridge 200 sized to permit such an operation. As the pusher 218advances, it contacts (or may be fastened to) the trailing edge 220 ofthe wedge 208, forcing the wedge/knife sled assembly 201 in thedirection D₁. During this initial motion, the knife 206 remainsunexposed substantially as illustrated in FIG. 21a until the pivot pin210 anchored in the wedge 208 contacts the front portion of the slot 212in the knife 206, whereupon the knife 206 advances with the wedge androtates upwardly through a cutting slot 222 in the cartridge 200 asillustrated in FIG. 22. At the moment that the pivot pin 210 contactsthe front portion of the sloe 212, the forward portion 224 in the slot217 of the driver retainer base 216 causes the knife 206 to pivotupwardly, such that the cutting edge of the knife 206 is above the plane207 of the cartridge 200, enabling the tissue to be cut, as illustratedin FIG. 23. This forward portion 224 of the slot 217 may be ramped ormay simply comprise a vertical wall at the front of the slot 217.

As previously described, as the wedge/knife sled subassembly 201 movesin the direction D₁ the wedge 208 forces the staple drivers 203 in thedirection D₂ to form the staples 204. The knife 206 follows closelybehind and cuts the tissue as the staples form.

Upon reaching the end of travel, the cutting edge 206a of the knife 206hits a stop 230 in the nose of the cartridge 200 (FIG. 22). The stop 230is preferably the end of the cutting slot 222 in the cartridge 200 asillustrated in FIG. 22. At approximately the same time, the rear 206b ofthe knife reaches a forward slot 232 in the driver retainer base 216,causing the rear of the knife 206b to drop downward in the direction D₄to a "parked" position, once again placing the knife 206 below thesurface 207 of the cartridge 200 as illustrated in FIG. 21b.Alternatively, the knife 206 may achieve an unexposed position withrespect to the surface 207 of the cartridge 200 by riding and/orpivoting down an inclined ramp 240 at the tip of the cartridge 200 (FIG.21a).

Preferably, both of the slots 217, 232 in the driver retainer 216 areformed within a longitudinal groove or track 234 in the base 216illustrated in FIG. 22. The cartridge 200 also preferably includeschannels 236 for slideably receiving the wedge(s) 208.

Once the knife 206 has advanced to its "parked" position, for example,by being retained in an unexposed position within the forward slot 232(FIGS. 21b, 23) or the inclined ramp 240, the pusher 218 may bewithdrawn, allowing the knife 206 to remain retracted in its "parked"position. At this point, the entire cartridge 200 may be discarded andreplaced with a similar cartridge having a new knife 206, staples 204,wedge sled 208, and having the knife 206 "parked" in the rearwardposition, retracted below the surface 207 as illustrated in FIG. 21a.

Preferably, the stop 230 in the nose of the cartridge 200 comprises andinwardly tapering portion of the slot 222, whereby as the unexposedcutting edge 206A of the knife 206 advances, it wedges within thetapered end of the slot 222, providing frictional retention of the knife206 in its unexposed position at the tip of the cartridge 200.

The knife 206 may be rigidly, pivotally, slidably, or releasably coupledto the wedge sled 208.

Most preferably, the knife 206 and wedge 208 are fastened to oneanother, either pivotally or rigidly, thereby comprising an integralwedge/knife assembly. This may be accomplished by providing a pivot pinpassing through both the knife 206 and wedge 208, by fastening the twocomponents to one another, e.g., by use of an adhesive, weldment, or byintegrally forming the two components during fabrication. In thisembodiment, as the knife/wedge assembly completes the cutting/staplingsequence, the entire assembly "parks" as illustrated in FIG. 21b, andonly the pusher or driver 218 is withdrawn.

In a preferred embodiment of this device, illustrated in FIG. 24, thewedge sled 208 includes a channel 250 for slideably receiving the knifesled 206. The wedge sled 208 includes a stop 252 proximate to the rearof the channel 250 against which the rear end 206c of the knife sled 206sits during a cutting sequence. The pusher rod 218 contacts or isfastened to the trailing edge 220 of The wedge 208, allowing the pusherrod 218 to advance the wedge 208 and knife sled 206 substantially aspreviously described. During the cutting sequence, the combination ofinertial forces on the knife 206 and resistance from tissue on thecutting edge 206a will force the rear end 206c of the knife 206 intocontact with the stop 252, enabling the wedge sled 208 to push the knife206 toward the front end of the cartridge 200.

Because, in the embodiment of FIG. 24, the knife 206 is slideablyreceived by the wedge sled 208, once the knife 206 reaches its "parked"position at the tip of the cartridge 200, it may remain in thatposition, allowing the wedge 208 to be retracted following the cuttingsequence, as illustrated in FIG. 25.

As further illustrated in FIG. 24, the knife sled 206 preferablyincludes a guide block 254, which is sized to a fairly close toleranceto the dimensions of the channel 250, thereby allowing the knife 206 toremain relatively stable prior to and during the cutting sequence. Forexample, the guide block 254 helps maintain the knife 206 in an uprightposition, may help frictionally retain the knife 206 within the wedge208 until after the cutting sequence is completed, and helps prevent"wavering" of the knife during the cutting operation. The guide block254 preferably also includes a channel 256 for pivotally receiving theknife 206. This channel 256 allows the knife 206 to pivot downwardly,either from the front portion of the knife about a pivot 210a or, allowsthe rear of the knife to pivot downwardly about a pivot 210b asillustrated in FIG. 24. Note that the pivots 210a and 210b arealternative pivots, and would not be used together on the sameinstrument.

Once the knife decoupling assembly of FIG. 24 reaches the end of thecutting sequence, and the cutting edge 206a of the knife is retained inthe tip of the cartridge 200, the wedge 208 is free to slide away fromthe knife 206, leaving the knife 206 in its "parked" position asillustrated in FIG. 25. In the case of a frictional tapered slotarrangement for wedging the cutting edge 206a of the knife in the tip ofthe cartridge 200, the frictional forces of the tapered slot 222 mustobviously be greater than any frictional forces acting on the guideblock 254 by virtue of the channel 250 in the wedge 208.

Another highly preferred embodiment of the invention is illustrated tinFIGS. 26-27, which will now be described. In this embodiment of theinvention, an improved locking mechanism for an articulating surgicalinstrument is provided. The mechanism may be used with linear staplercutters such as previously described, but may also be used with otherarticulating surgical instruments, such as open and endoscopic surgicalstapling, cutting, applying, and grasping instruments.

In general, the mechanism operates to lock the articulatable head of asurgical instrument at an angle of articulation with respect to a rigidshaft to which the head is articulatably mounted. One such mechanism forperforming the locking operation as illustrated in FIG. 26. In thisdevice, the instrument, generally 300, includes a head, generally 302,articulatably mounted to a rigid shaft, generally 304, by anarticulation joint 306, pivotally attaching the head 302 to the shaft304.

The instrument 300 includes a device for transferring work from theproximal end of the instrument, which may include a handle/triggermechanism substantially as previously described. This work transferringdevice allows the operator of the instrument 300 to control thearticulation of the head 302 with respect to the shaft 304. In theembodiment of FIG. 26, an articulation band 308 is employed. Preferably,a pair of articulation bands 308 are used, one on either side of theinstrument 300. In the embodiment of FIG. 26, the articulation band 308aon the right side of the instrument articulates the head 302 in aclockwise direction when the band 308a is pulled toward the proximal endof the instrument 300. Conversely, the band 308b on the left side of theinstrument articulates the head 302 in a counterclockwise direction whenpulled toward the proximal end of the instrument 300. The articulationbands 308a and 308b may comprise two sections of the same band, loopedaround a pulley or similar device at the proximal end of the instrument.

In a most highly preferred embodiment of the locking mechanism of theinvention, the mechanism locks the head 302 at an angle of articulationat all times except when it is desired to articulate the head 302 withrespect to the shaft 304. Upon actuation of the articulation device, forexample by pulling the articulation band 308a toward the proximal end ofthe instrument 300, the locking mechanism of the invention releases,unlocking the head 302 and allowing articulation thereof.Discontinuation of the articulation step, for example, by stoppage ofpulling forces on the articulation band 308a, causes the lockingmechanism of the invention to reengage, locking the head 302 of theinstrument 300 in its new angle of articulation.

The details of the preferred locking mechanisms of the present inventionwill now be described. It is to be understood than these details aredescribed, for convenience, with respect to only one of the articulationbands 308a; however, in general, it is preferred that there be acomplimentary locking mechanism operatively engaged with the otherarticulation band 308b substantially as shall now be described withrespect to the articulation band 308a.

As illustrated in FIG. 26, the locking mechanism, generally 310,operatively engages the articulation band 308a. The articulation band308a in effect provides a linkage connecting and allowing work to betransferred, from the proximal end of the instrument 300 to the distalend thereof. The linkage of FIG. 26 is longitudinally movable withrespect to the shaft 304, and is fastened at the distal end of theinstrument to the head 302 at a point spaced from the centerline C1 ofthe head 302, allowing the head 302 to be articulated about the pivot306 when pulling (or, in the case of a stiff band, pushing) forces areexerted on the articulation band 308a.

Although the articulation band 308a of the embodiment of FIG. 26 appearsas a flat band, which is preferably a flexible metal such as stainlesssteel, or a flexible polymeric material, it will now be readilyunderstood by those of ordinary skill in the art that other linkagestructures, such as rods, cables, wire, etc., of these and othermaterials could likewise be employed for articulation.

Referring again to FIG. 26, a preferred locking mechanism of the presentinvention includes a pawl 312 which engages a ratchet 314 at theproximal end of the head 302. The ratchet 314 is preferably circular orsemicircular in shape, and the pivot point 306 is preferably located atsubstantially the center of the circle defined by the ratchet 314. Thepawl 312 is pivotally connected to the shaft 304 via a pivot pin 316.The pawl 312 is biased into locking engagement with the ratchet 314 by abiasing mechanism, such as a spring 318. In the embodiment of FIG. 26,the spring 318 is anchored to the shaft 304 by a pin 320.

The pawl 312 includes an engagement pin 322 which engages thearticulation band 308a as illustrated. The articulation band 308a iseither flexible along its entire length, or is at least flexible in theregion 309 that passes around at the engagement pin 322. The entirelocking mechanism 310 is supported by an upper support plate 324 whichmay include a complimentary lower support plate 326. The support plates324, 326 may be housed within the tubular shaft 130 previouslydescribed.

The locking mechanism 310 operates as follows: when the articulationband 308a is tensioned, for example, by being pulled toward the proximalend of the instrument 300 by the operator thereof, the band 308a tendsto straighten out in the flexed region 309 where the band 308a bendsaround and behind the engagement pin 322. As the flexed section 309 ofthe band 308a is pulled, it tends toward a linear orientation withrespect to the remainder of the band 308a, causing the band 308a to acton and push the engagement pin 322 in the direction D5, compressing thespring 318, thus rotating the pawl 312 clockwise about the pivot 316,thereby releasing the pawl 312 from its locking engagement with theratchet 314. The engagement pin 322 is free to slide in the direction D5within a slot 323 in the upper support plate 324. The lower end of theengagement pin 322 may rest on the upper surface of the lower supportplate 326 as illustrated.

Once the pawl 312 has been released from the ratchet 314 as described,the tensioning forces acting on the articulation band 308a cause theinstrument head 302 to articulate about the articulation pivot 306.

As will, of course, be readily appreciated by those of ordinary skill inthe art, although the articulation band 308a is described is providingarticulation through a tensioning or pulling movement, it would beequally possible to induce articulation through the use of pushingforces, for example, by using a rod in place of the articulation band308a having a flexible section 309 therein. Although the embodiment ofFIG. 26 is shown with a flexible portion 309 in the articulation band308a, it would, of course, also be possible to drive the engagement pin322 in the direction D1 without using a flexible portion 309. Such adevice could include, for example, a stiff rod in place of the band 308ahaving fastened thereto an outwardly tapering wedge forcing theengagement pin 322 in the direction D5 as the rod is pulled or pushedtoward the proximal end of the instrument 300.

Returning now to FIG. 26, when tension on the articulation linkage 308ais relaxed, for example, following actuation of the articulationmechanism, the spring 318 is free to push the pawl 312 back into lockingengagement with the ratchet 314, thus locking the head 302 at its newangle of articulation. In the embodiment of FIG. 26, the spring 318 isfirmly grounded to the upper support plate 324, which is firmly attachedto the support tube 130 of the instrument.

When the other articulation band 308b is tensioned, a mechanism similarto the locking mechanism 310 on the opposite side of the support platesfunctions as previously described. A similar pawl 312 is arranged toallow the head 302 to rotate counterclockwise with a minimum ofresistance, but to lock when the head 302 is rotated clockwise. Thus,the locking and unlocking mechanism is symmetric, and functions formotion in either a clockwise or counterclockwise direction. In theembodiment of FIG. 26, the lower pawl 312 would engage a lower ratchet315 on the head 302.

Another preferred embodiment of the articulation locking mechanism ofthe present invention is illustrated in FIG. 27. This embodimentincludes a friction lock, which will now be described. In the device ofFIG. 27, a pair of opposed articulation bands 408a and 408b pass througha shift, generally 404, through an articulating coupling 406 to the head402 of the instrument. The bands 408a and 408b are attached to the head402 at points 402a and 402b, respectively, each spaced from thecenterline C2 of the head 402.

Although the flexible coupling 406 of the embodiment of FIG. 27 isillustrated as a flexible neck, a pivot pin coupling similar to thatdisclosed in FIG. 26, or other articulation couplings known to those ofordinary skill in the art could also be employed.

In The embodiment of FIG. 27, a pair of biasing devices, such as springs418a and 418b each bias an engagement pin 422a, 422b, respectively,against a flexed portion 409a, 409b, of the articulation bands 408a,408b, respectively. Each pin 422a, 422b is attached to a locking cam412a, 412b, respectively, and the locking cams 412a, 412b are pivotallymounted to the shaft 404 by pivot pins 416a, 416b, respectively. Eachlocking cam 412a, 412b includes a locking surface 413a, 413b,respectively, which frictionally engages, or otherwise locks the bands408a, 408b, respectively, as illustrated. These locking surfaces 413a,413b are forced into locking engagement with their respective bands bythe biasing springs 418a, 418b, which pivot their respective cams abouttheir respective pivot points.

Referring now, for convenience, to only one of the friction lockingmechanisms, in operation, tension on the articulating band 408a causesthe flexed portion 409a of the band to pull on the engagement pin 422a,causing the locking cam 412a to pivot about its pivot 416a, releasingthe locking surface 413a of the locking cam 412a from its lockingengagement with the other articulation band 408b. The release of thearticulation band 408b by the locking cam 412a followed by continuedtension on the articulating band 408a allows the head 402 to articulatein a counterclockwise direction about the articulation connection 406.Releasing tension on the band 408a allows the spring 418a to push,thepin 422a, forcing the locking cam 412a back into locking engagement withthe articulation band 408b, locking the head 402 in its new angle ofarticulation.

Alternative articulation locking mechanisms of the present invention areillustrated in FIGS. 28-31, which will now be described.

Referring now to FIGS. 28A and 28B, there is illustrated a lockingmechanism comprising a ratchet 514 at the proximal end of the head,generally 502. The locking mechanism also includes a gear rack 512,which is capable of achieving locking engagement with the ratchet 514 bysliding the gear rack 512 distally toward the rack 514 in the directionD2 illustrated in FIG. 28B.

Preferably, the device of FIGS. 28A and 28B includes a biasing device,such as a spring, (not shown) which biases the gear rack 512 intolocking engagement with the ratchet 514 prior to and following actuationby the articulation control mechanism of the instrument, the biasingdevice releasing the gear rack 512 upon actuation of the articulationmechanism, permitting articulation of the head 502 substantially aspreviously described. The rack 512 may be slideably positioned on theoutside of the shaft 504 as illustrated in FIG. 28B, or it may bepositioned internally thereof. The head 502 is articulatably mounted tothe shaft, for example, at a pivot point 506 as illustrated.

Another preferred locking mechanism of the present invention isillustrated in FIG. 29. In this embodiment, the head, generally 602,includes at the proximal end thereof a detent device 614 having aplurality of detents 615 therein, and further includes a locking blade,generally 612, which may be biased into locking engagement with thedetent 614, for example, by a spring, thereby locking the head 602 priorto and following articulation thereof by at articulation joy stick 650.In the embodiment of FIG. 29, the articulation band 608 is a one-pieceflexible band attached to either side of the head 602 as illustrated,and passes around a pulley 652 attached to a shaft 654 driven by the joystick 650. As illustrated in FIG. 29A, the locking blade 612 may beforced into locking engagement with the detent 614, either manually, orwith a biasing spring or other automatic locking device such aspreviously described. The head 602 pivots about an articulation pivot606 substantially as previously described. In the embodiment of FIG. 29,the locking blade 612 may be manually disengaged prior to articulation,for example, by simply sliding the bar 612 out of engagement with thedetent 614 as illustrated in FIG. 29B. After articulation, the bar 612may be slid back into locking relationship with the detent 614 asillustrated in FIG. 29C, locking the head 602 in its new angle ofarticulation.

Turning now to FIGS. 30-31, there is illustrated yet another preferreddevice for locking the head of an articulating surgical instrument. Thisdevice includes a head 702 articulatably mounted to a shaft 704 at apivot 706, as illustrated In FIG. 30. The device further includes afluid-filled bladder assembly, generally 714, for providing locking ofthe articulatable head 702. As best seen in FIG. 30A, the bladderassembly 714 preferably includes two interconnected bladders 714a and714b connected by a connecting region 715. Fluid is free to flow betweenthe bladders 714a and 714b through the connecting region 715 except whenthe bladder assembly 714 is acted upon by a pinch blade 712 which can bemoved distally into a pinching orientation with the connecting region715. As illustrated the bladders 714a and 714b are each supported by asaddle 713a and 713b respectively. The saddles are sized to allowcomplete inflation of each bladder with the full compliment of fluidcontained in both bladders 714a and 714b combined.

As used herein, the term "fluid" comprises liquids, gases, gels,microparticles, and any other material which can be made to flow betweena pressure gradient.

in operation, the device of FIGS. 30-31 operates as follows: the pinchblade 712 is withdrawn, opening the connecting region 715 to fluid flowbetween the bladder 714a and 714b. This In effect opens a "valve"between the two bladders as schematically illustrated in FIG. 31A. Thehead 702 is then capable of being articulated by moving one or born ofthe articulation bands or straps 708a/708b. As illustrated in FIG. 31,if the head 702 is to be articulated in a clockwise direction, the band708a is pulled proximally, rotating the head 702 about the pivot 706 ina clockwise direction as illustrated.

Referring again to FIG. 31, as the head 702 is articulated, in thedirection shown, the bladder 714a is deflated, as the proximal end ofthe head 702 forces fluid through the opened connecting portion 715 intothe other bladder 714b, enlarging that bladder as illustrated. Once thedesired angle of articulation is achieved, the pinch blade 712 may againbe forced into a closing/pinching relationship with respect to theconnecting portion 715 of the bladder assembly 714 and the rear of thehead 702, thereby precluding any further fluid flow from one bladder714a/714b to the other, closing the "valve" as schematically illustratedin FIG. 31B. Once this is achieved, the head 702 is effectively lockedin its articulated position. As illustrated in FIGS. 31a and 31b, thepinching blade 712 effectively acts as a valve, opening and shutting offfluid flow from one bladder to the other.

The pinch blade 712 may be manually operated, or may be attached to abiasing device in order to maintain the pinch blade in a biasedposition, closing off the connecting portion 715 until articulation isdesired, at which point the pinch blade 712 may be removed from itsbiased position, opening the connecting portion 715.

Yet another preferred aspect of the present invention, an improved anvilclosure mechanism, is illustrated in FIGS. 32-35. Referring now to FIGS.32A, 32B, and 33, there is illustrated the distal portion of a surgicalinstrument including a shaft 830 with an anvil, generally 840, and alower jaw 832, which holds a staple cartridge 850. The anvil 840includes an upper jaw portion 842 which, as illustrated in FIGS. 32-33,is adapted to be opened and closed with respect to the lower jaw 832 forpurposes of clamping and releasing tissue between the jaws 832/842.

The embodiments of FIGS. 32-35 may be beneficially employed with respectto any of the surgical instruments previously described, whichinstruments generally comprise a handle connected to a shaft to whichthe fastener applying or other surgical working assembly is attached atits distal end. The embodiments of FIGS. 32-35 may furtheradvantageously be used with surgical instruments having a fastenerapplying assembly including a fastener holder, such as a cartridge, 850for holding one or more surgical fasteners, a driver for driving thesurgical fasteners from the cartridge into the tissue, substantially aspreviously described, and a device such as the anvil 840 for forming thesurgical fasteners about the tissue. The device of FIGS. 32-35 alsopreferably includes a closure mechanism for closing the anvil and thefastener holder 850 with respect to each other and for clamping tissuebetween the jaws 842 and 832. Preferably, the instrument also preferablyincludes a device for actuating the closure mechanism (subsequentlydescribed) and the handle preferably includes a device, such as atrigger mechanism for actuating the staple drivers and firing thesurgical staples into the tissue, also substantially as previouslydescribed. It is preferred, of course, than the handle of these devicesbe mounted to the proximal end of the shaft 830.

Turning now to the specific features of the anvil closure mechanisms ofFIGS. 32-35, and referring specifically no FIGS. 32-33, a preferredclosure mechanism of the invention includes a closure tube, generally838, rotatably mounted to the shaft 830. Preferably, the device alsoincludes a knob or other mechanism 820 attached to the closure tube 838for rotating the closure tube 838 with respect to the shaft 830. In ahighly preferred embodiment of the invention, the closure tube 838comprises a unitary part of the shaft 830, such that when the shaft 830is rotated, the closure tube 838 necessarily rotates as well withrespect to the anvil 840.

Referring now to FIGS. 32A and 328, the preferred closure mechanismopens the jaws 832, 842, with respect to each other, when the closuretube 838 is rotated in a first direction R1, and closes the jaws 842,832 with respect to each other when the closure tube 838 is rotated inthe opposite direction R2 via the rotation knob 820. Preferably, theanvil 840 is pivotally mounted to the lower jaw 832 via a pivot pointwhich may be a pin 839 embedded in a slot or hole in the lower jaw 832.Alternatively, if the shaft 830 and closure tube 838 are not integral,rather the shaft is fixed with respect to the anvil 840, it would befeasible for the pin 839 to be rotatably mounted within the shaft 830.

Referring now to FIG. 33, a preferred mechanism for allowing the closuretube 838 to open and close the anvil 840 with respect to the staplecartridge 850 includes a flange 860 proximate the distal end 838a of theclosure tube 838. The flange 860 engages a beveled slot 862 formed inthe heel 864 of the anvil 840. As the closure tube 838 is rotated in afirst direction R1, the flange 860 rotates into the beveled slot 862,forcing the anvil 840 to pivot upwardly in the direction P1 about thepivot point 839.

As further illustrated in FIG. 33, the closure tube 383 includes acutout portion 866 adjacent the flange 860. The cutout portion is sizedto allow the anvil 840 to open to a fully opened position, by allowingthe upper surface 827 of the heel 864 to pass outside of the cylinderdefined by the closure tube 838, as the flange 860 is rotated into thebeveled slot 862.

The closure tube 838 also preferably includes a projecting portion 868proximate the cutout portion 866. The projecting portion 868 engages theupper surface 827 of the heel 864 of the anvil 840 as the closure tube838 is rotated in a second direction R2 opposite from the firstdirection R1. This causes the anvil 840 to pivot about the pivot point839 (FIG. 32B) to a closed or clamped position as schematicallyillustrated in FIG. 32A, allowing tissue to be clamped between the anvil840 and the staple cartridge 850.

In another preferred embodiment of the invention, the closure tube 838,rather than including a flange 860, includes an inner thread or othersurface having an inclined portion, which may comprise the inner wall ofthe closure tube 838, which inclined portion urges the anvil 840 closedwith respect to the staple cartridge 850 as the closure tube is rotatedin the second direction R2. In this embodiment, the inclined surfacewould act on the upper surface 827 of the heel 864 of the anvil 840, andwould preferably act against a biasing device, such as a spring urgingthe anvil 840 open with respect to the staple cartridge 850.

Other embodiments for achieving opening and closure of the anvil 840with respect to the staple cartridge 850 will now be readily apparent tothose ordinarily skilled in the art, including elliptical closure tubes838, and variations on the flange/inclined slot embodiment, includinginclined tracks, threads, etc.

Another preferred anvil closure mechanism of the invention isillustrated in FIGS. 34A and 34B. In this embodiment, the closuremechanism includes a wedge 960 slideably received by an inclined slot962 in the anvil 940. The wedge 960 of FIGS. 34A and 34B is pivotallyconnected to a rigid channel 932 which may comprise a lower jaw having astaple cartridge therein. The pivotal connection between the wedge 960and channel 932 may be achieved by a pin 934 passing through one end ofthe wedge 960 and through the channel 932.

The wedge 960 of the embodiment FIGS. 34A and 34B is also pivotallyconnected by a pivot 936, at a point spaced from the pivot 934, to adrive shaft 938. This pivot 936 may also comprise a pin passing throughboth the drive shaft 938 and the wedge 960. The pivots 934 and 936 allowthe driver 938 to drive the wedge 960 about the pivot 934. The driver938 is preferably a rigid member, such as a rod slideably received bythe shaft 930. Most preferably, the driver 938 includes a lever device,generally 920, for sliding the driver 938 distally and proximately withrespect to the shaft 930. This device 920 may comprise, for example, alever 922 which may be pivoted upwardly in a first direction L1, andpivoted downwardly in a second direction L2.

The lever 922 is pivotally fastened to the shaft 930 at a pivot point934, which may be a pin passing through a flange 926 mounted to theshaft 930. The lever 922 is also pivotally connected at a pivot 928 to alinkage 927 which, in turn, is connected pivotally at a pivot 929 to alever rod 925. The lever rod 925 is slideably supported by a secondflange 923. The flange 923 is also fastened to the shaft 930. The leverrod 925, in turn, is fastened to a second linkage 921 which is slideablyreceived by the driver 938 and captured by a pair of flanges 917 and918.

In operation, the driver 938 is pulled rearwardly, for example, bypushing the lever 922 down in the direction L2, causing the linkage 921to slide rearwardly on the driver 938, contacting the rear flange 918and pulling the driver 938 rearwardly. This, in turn, causes the wedge960 to pivot in a clockwise direction about the pivot 934, causing theanvil 940 to rotate about its pivot 939 to an open position asillustrated in FIG. 34A. The wedge 960 includes an upper surface 961which contacts a rearward inclined surface 963 of the incline slot 962.As the wedge 960 rotates in a clockwise direction, the upper surface 961rides against the rear inclined slot surface 963, causing the anvil 940to pivot upwardly about the pivot 939.

When it is desired to close the anvil 940, driver 938 is simply pushedforward, for example, by lifting the lever 922 it the direction L1which, through the various pivots and link-ages of the lever mechanism920, causes the linkage 921 to slide forwardly until it contacts theforward flange 917, pushing the driver 938 in the forward direction.This, in turn, causes the wedge 960 to rotate counter-clockwise aboutthe pivot 934 as illustrated in FIG. 34B. The wedge 960 includes a lowersurface 965 which contacts a forward inclined surface 967 of the inclineslot 962 as the lever 960 is driven forward by the driver 938. This, inturn, causes the wedge 960 to drive the anvil down, about the pivot 939into a closed orientation with respect to the channel 932 as illustratedin FIG. 34B.

In another preferred embodiment to the invention, the same or similarlever mechanism 920 is used, but with a different wedge system, asillustrated in FIG. 34C. In this embodiment, the wedge driver 1038 isrigidly connected to the wedge 1060 (i.e., without any pivots). Thewedge 1060 comprises an inclined flange having a rear inclined surface1061 and a forward inclined surface 1065. The flange 1060 is slideablyreceived within an inclined slot 1062 in the anvil 1040. As illustrated,the inclined slot 1062 inclines upwardly in a direction from the distalend of the anvil 1040 to the proximal end thereof. In the embodiment ofFIG. 34c, as the driver 1038 is pulled rearwardly in the direction D6,the rear surface 1061 of the inclined flange 1060 contacts the rearsurface 1063 of the inclined slot 1062, drawing the anvil 1040downwardly about the pivot 1039. The pulling force exerted on the driver1038 can be increased, for example, by utilizing a lever mechanismsimilar to that of FIG. 34A, generally 920. The harder the pullingforces exerted on the driver rod 1038, the greater the clamping forcesresulting from the anvil 1040 clamping against the lower jaw 1032.

To open the anvil 1040 of FIG. 34C, the driver 1038 is simply pushed inthe opposite direction (toward the distal end of the instrument), whichcauses the forward surface of the inclined flange 1065 to slide againstthe forward inclined surface 1067 of the slot 1062, which in turn causesan anvil 1040 to ride upwardly about the pivot 1039.

Another highly preferred anvil closure mechanism of the presentinvention is illustrated in FIG. 35. In this embodiment, the anvil 1140includes one or more pivot pins 1139 which ride in openings 1139a andthe sides of the lower channel 1132, which contains a staple cartridgesubstantially as previously described. The rear end of the anvil 1140also includes a tongue 1141 having a "nib" or other connecting point1160 at the end thereof. This connecting point 1160 is spaced from theaxis A1 of the anvil 1140 as illustrated. The tongue 1141 is preferablyoriented substantially perpendicular with respect to the frontal portion1140a of the anvil 1140. When mounted to the channel 1132, the anvil1140 is able to pivot about the pivot point 1139 and about the axis A1.

The connection point 1160 is connected to an anvil driver 1138 whichpasses through the shaft 1130 to the handle of the instrument, whichincludes a mechanism such as a trigger, for actuating the driver 1138proximately and distally with respect to the handle. When the driver1158 is pulled rearwardly, a force F1 results, pulling on the connectionpoint 1160 of the tongue 1141, creating a moment M1 about the axis A1,resulting in the clamping or closure of the anvil 1140 with respect tothe channel 1132. Conversely, when an opposite force F2 is placed on thedriver 1138, which is preferably a stiff member such as a rod, thedriver 1138 drives the connection point 1160 of the tongue 1141 in theforward direction, creating a moment M2 about the axis A1, and pivotingthe anvil 1140 open with respect to the channel 1132. It is preferredthat the connection point 1160 not be rigidly fastened to the driver1138, rather that there be some "play" between these two components, toallow the opening and closing action of the anvil 1140 to take place.

In the embodiment of FIG. 35, the connection nib 1160 is locatedsubstantially along the centerline CL of the tongue 1141 as illustratedin FIG. 35A. The connection point 1160 of FIG. 35A is also positioned"inboard" of the axis A1 with respect to the fastener holding channel1132. This provides a fulcrum for leveraging the closure forces F1 asthe anvil driver 1138 is drawn rearwardly. It is preferred that thedistance L3 between the axis A1 and connection point 1160 be maximizedwithin the confines of the instrument, thereby maximizing the clampingforces available.

The embodiment of FIG. 35 includes a joy stick for providingarticulation of the channel 1132. The device is also shown with a knife1106 for use in a linear cutter, substantially as previously described.A driver shaft for this knife or other surgical instrument may passthrough a slot 1104 in the tongue 1141 as illustrated.

Yet another highly preferred embodiment of the present invention isillustrated in FIGS. 36-42. In this embodiment, a flexible neck or"flex-neck" mechanism is provided for allowing the articulation of thehead assembly of a surgical instrument. One of the advantages of aflexible neck articulating attachment is the smoother "sweep" achievedby this method of articulation, which is preferred by some surgeons.Additionally, as seen FIG. 36, a flexible neck provides for a relativelylarge bend radius "R," which a allows a relatively smoother transmissionof forces around the bend as will now be described.

Referring now to FIG. 36, there is illustrated a preferred flexible neckassembly, generally 1200, of the present invention. This assembly 1200is beneficially used with respect to any articulatable surgicalinstrument, such as those having a handle connected no a shaft 1230having a head assembly, generally 1240, including a surgical component,such as a linear stapler/cutter, associated therewith. The head assembly1240 is articulatably mounted to the distal end of the shaft 1230 by aflexible neck member 1260 comprising a flexible material having at leastone axial kerf 1262 therein. As illustrated, the axial kerf(s) enablethe flexible material of the flexible neck 1260 to bend along thekerf(s) along a bend radius "R" defined by the flexible neck 1260. Thisbend radius "R" allows for the smooth transmission of force around abend with the use of flexible members, for example, for driving stapledrivers, wedges, knives, etc. The articulatable surgical instrument alsoincludes a mechanism for providing articulation to the head assembly,the mechanism being proximate the handle for providing remotearticulation of the head assembly along the bend radius "R."

Most preferably, the flexible neck 1260 includes a plurality of kerfs1262 separated by ribs 1269 as illustrated in FIG. 36. These kerfs 1262and ribs 1269 are preferably equally spaced along the flexible neck1260, thereby promoting a consistent bend radius "R" when the flexibleneck 1260 is articulated. Of course, a flexible neck having multiplebend radii may be achieved by providing unequal space between the kerfsand the ribs, for example, spacing the ribs more closely at one end,such as the distal end of the flexible neck, and farther apart at theother end, such as the proximal end of the flexible neck, as illustratedin FIG. 36a. As will now be readily apparent to those of ordinary skillin the art, increasing the spacing of the kerfs and/or ribs reduces thebend radius of the section having increased spacing, more closelyapproximating a pivot point bend connection. Conversely, spacing thekerfs and/or ribs more closely results in a more gradual bend, having alarger bend radius.

In the embodiment illustrated in FIG. 36, the kerfs 1262 compriseannular grooves that extend at least partially around the perimeter ofthe flexible neck 1260. The kerfs 1262 preferably, however, comprisesemi-annular grooves which are separated by a central longitudinal rib1264 passing down the centerline C/L of the flexible neck 1260. This rib1264 assists in providing stiffening to the flexible neck 1260,including sagging thereof, connects the ribs 1269, and provides astructure for receiving a slot 1266 therethrough for receiving surgicaltools, such as a knife, a driver bar for pushing wedge blades fordriving staples, or other surgical devices. This rib 1264 also allowstransmission of force through the central, neutral, axial plane of theflexible neck, thus permitting the neck to be a means of pushing andpulling a tube distal to the neck, so that the jaw elements can beforcibly closed and opened. The longitudinal rib 1264 preferably runsthe entire longitudinal length of the flexible neck 1260. The flexibleneck 1260 also preferably includes a pair of side slots 1268 passingthrough each rib 1269. The ribs 1269 as illustrated in FIG. 37preferably comprise disc-shaped portions which border each of the kerfs1262 as illustrated in FIG. 36. Each of the discs 1269 includes at leastone outboard slot 1270 spaced-from the centerline C/L of the flexibleneck by a distance D8 as illustrated in FIG. 37.

Art alternative embodiment of the flexible neck is illustrated in FIGS.39-41. In this embodiment, the kerfs 1262 comprise herringbone-shapedgrooves in the flexible neck 1260 as illustrated. The herringbone-shaped grooves 1262 are preferably angled rearwardly (or forwardly)with respect to the axis A1 of the flexible neck 1260, preferably at anangle of about 30° with respect the axis A1 when the flexible neck 1260is in a linear orientation as illustrated. The herringbone kerfs 1262provide for a smaller bend radius "R" than the embodiment of FIGS.35-38. These grooves also allow the series of kerfs to interlock whenthe flexible neck is in the full, bent orientation, providing theflexible neck with increased torsional stiffness about the longitudinalaxis. This increases the usefulness of the instrument for grasping andmanipulating tissue. As illustrated in FIG. 40, the herring bone-shapedgrooves are joined via a longitudinal rib 1264 which is offset from theaxis A1 of the flexible neck 1260, and functions as a "backbone" for theherringbone-shaped ribs 1269. As illustrated in FIG. 41, the flexibleneck 1260 of FIGS. 39-41 may include a central bore 1266 for receivingvarious surgical manipulating devices as previously discussed.

Each of the flexible necks of FIGS. 35-41 preferably includes a rearcollar 1272 for securing the flexible neck within the shaft 1230 end aforward collar 1274 for securing the flexible neck to the head assembly1240, for example, with a friction fit, crimp, fastener, or otherfastening device.

The flexible material of the flexible neck 1260 may be of any suitablematerial, but preferably is a material which provides sufficientstiffness to transmit axial force and to allow the head assembly 1240 ofthe instrument to be inserted through a trocar or cannula, yet flexibleenough to provide for the articulation described and illustrated herein.Examples of flexible materials which may be advantageously used with theflexible neck of the present invention include by way of example but notlimitation, polycarbonates, nylon, high density polyethylene, rubber,neoprene, polyester, polytetrafluoroethylene (Teflon®), polypropylene,polyetherimide, and poly(vinyl chloride) PVC!.

Referring now to FIGS. 42 and 43, the flexible neck 1260 of theinvention is preferably articulated by an actuation device, generally1280, located proximate the handle at the distal end 1230a of the shaft1230. In the embodiment of FIG. 42, the actuation assembly 1280comprises a joy stick or lever 1282 rotatably received by a collar 1284and having an axle 1286 fastened thereto. The collar 1284 furtherincludes a knob 1288 which may be used for rotating the shaft 1230 andalso rotating the head assembly 1240. The knob 1288 preferably providesa connection between the shaft 1230 and the handle of the device (notshown). The preferred embodiment of the invention also includes amechanism for transferring force from the actuation means 1280 to thehead assembly 1240. This force transfer mechanism may comprise aflexible member, such as a flexible band 1290 illustrated in FIG. 43.The flexible band 1290 is preferably connected at its distal end to thehead assembly at a point spaced from the axis of the head assembly atthe point 1290A illustrated in FIGS. 36 and 42. Although the flexiblemember 1290 is illustrated in FIG. 43 at a flexible ribbon, which maycomprise stainless steel, it will now be readily appreciated by those ofordinary skill in the art that the flexible member 1290 may alsocomprise a rod, strap, band, cable, chain, or wire. The flexible member1290 is preferably fastened at its proximal end 1290b to the axle 1286,for example, with a pin passing through a hole 1291 in the band 1290 and1287 in the axle 1286. The flexible member 1290 is slidably receivedwithin the slots 1270 of the flexible member 1260 illustrated in FIG.37. These slots 1270 are also spaced from the axis A1 and centerline C/Lof the flexible member 1260.

Preferably, two flexible members 1290 are slidably received by two slots1270 in the flexible member 1260. A first flexible member 1290articulates the head assembly in a first direction and a second flexiblemember 1290 articulates the head assembly 1260 in a second directionopposite the first direction.

In the embodiment of FIG. 42, for example, one band 1290 wouldpreferably he positioned on one side of the axle 1286 and a second band1290 would be fastened to the other side of the axle 1286. Rotating thelever 1282 in a counterclockwise direction D9 would cause the band 1290fastened to the front side of the axle 1286 to be pulled rearwardly, andwould cause the band 1290 fastened to the rear side of the axle 1286 tobe pushed forwardly, the net effect being the articulation of the headassembly 1240 in a counterclockwise direction D10. Similarly, if thecontrol lever 1282 is rotated clockwise, the head assembly 1240 isarticulated clockwise in the direction D11.

In a most highly preferred embodiment of the invention, the bands 1290are fastened at their distal ends to the proximal end of the headassembly 1240, substantially as previously described, but the bands 1290are fastened at their proximal ends to a rigid pusher rod which, inturn, is fastened at its proximal end to the actuation axle 1286. Inthis way, the pushing forces acting on the flexible member 1260 can bemore efficiently utilized. The pusher rods may be connected to the axle1286, for example, with a loose-fitting pin or other fastening mechanismthat allows the axle 1286 to push and pull the rod with respect to theshaft 1230 as the axle 1286 is rotated by the lever 1282. Otheractuation mechanisms 1280 for providing remote articulation of the headassembly 1240 with respect to the shaft 1230 may be employed.Furthermore, articulation actuation devices such as a knob having a wormdriving a worm gear, such as disclosed in co-pending application Ser.No. 08/219,846, incorporated by reference herein, may also be used withthe articulation flexible neck 1260 of the present invention.

In another preferred embodiment of the invention, illustrated in FIG.44, the flexible member includes a central slot 1266 which receives aband comprising a composite material, for example, a pair of stainlesssteel pins 1210, 1212, having a polymeric driver, such as Vectra®(manufactured and marketed by Hoescht) 1214 sandwiched therebetween.This composite driver may drive a knife/wedge fork 1216 such asillustrated in FIG. 44. The embodiment of FIG. 44 also includes a pairof channels 1218 therein, each of which receives a wire tension cable1219 which is anchored to the head assembly 1240 at a point 1219a spacedfrom the axis A1 of the head assembly 1240 as illustrated. It thisembodiment, articulation is achieved by pulling one of the wire tensioncables 1219 rearwardly, which causes the head assembly 1240 toarticulate in the direction of pull of the wire tension cable 1219. Theembodiment of FIG. 44 also preferably includes a metal ring 1215 whichpresses to the collar 1274 of the flexible member 1216, providing hoopstrength. This same ring 1215 may also comprise an anvil closure ringsuch as previously described.

Yet another preferred embodiment of the flexible neck of the inventionis illustrated in FIGS. 45-49. In this embodiment, a device, generally1300, for articulatably mounting a surgical component to a shaft isillustrated. The device 1300 comprises a flexible neck having apredetermined arcuate set as illustrated in FIG. 45. This may beachieved, for example, by injection molding the flexible neck 1360 inthe preset arcuate bend as illustrated. The preset flexible neck 1360also includes a plurality of teeth 1362 which mesh with correspondingkerfs 1364 as illustrated in FIGS. 45 and 46. Each of the teethpreferably has a beveled facing surface, 1396, 1398, as illustrated.

Preferably, the preset flexible neck 1360 comprises two separatesections, a top section 1366 and a bottom section 1368. IN theembodiment of FIGS. 45-49, each of the two preset flexible neck sections1366, 1368, is clamped together, for example, with a first spring 1370at the proximal end and a second spring 1372 at the distal end. Theflexible neck 1360 is preferably sheathed within a flexible outer tubeor sleeve 1374, which allows the neck 1360 to achieve its predeterminedarcuate set as illustrated in FIG. 45.

If the flexible neck 1360 is molded in a predetermined arcuate set, itis also necessary to include a sleeve or other mechanism forstraightening the flexible neck 1360 as illustrated in FIG. 46. In thisembodiment, a stiff outer tube 1376 could be used to slideably receivethe flexible neck 1360, either by pushing the stiff tube 1376 over theneck 1360, or withdrawing the flexible neck 1360 into the stiff tube1376.

In a most highly preferred embodiment of the invention, the flexibleneck 1360 is molded in a straight orientation such as illustrated inFIG. 46, with the teeth 1362 and kerfs 1364 positioned out of alignmentas illustrated. In this embodiment, there is no need for a stiffeningtube 1376 for straightening, rather, a flexible tube 1374 is used toallow the flexible neck 1360 to assume its arcuate shape as the tube1374 is passed over the neck 1360, applying axial pressure to each ofthe two sections 1366, 1368, as illustrated in FIG. 45. As the offsetteeth 1362 engage their respective kerfs 1364 upon application of axialpressure to the top and bottom sections 1366, 1368, normal forces N acton the facing surfaces 1396, 1398, of the teeth of the top and bottomsections 1366, 1368, respectively, forcing the neck 1360 to bend asillustrated in FIG. 45 in order to allow the teeth 1362 of each section1366, 1368, to achieve full engagement with the offset kerfs 1364 of theother section, 1368, 1366, respectively. The flexible sleeve 1374 musthave a relatively high hoop tension no allow sufficient pressure to beapplied to the flexible neck 1360 in order to achieve and maintain thearcuate bend of FIG. 45.

As illustrated in FIGS. 48-49, the flexible member 1360 includes anaxial channel 1380 defined by a pair of slots 1380a, 1380b, in eachsection of the flexible neck, 1366, 1368, respectively. The axialchannel 1380 is sized to permit the flexible neck 1360 to rotatably,slideably, threadably, or fixedly receive therethrough any of a numberof surgical actuation devices, electrical wires, and driver or puss/pullmechanisms, such as pusher rods, pulling cables, wires, bands, ribbons,rotative drill bit drivers, etc., for performing surgical functions atthe head assembly of a surgical instrument such as clamping, cutting,stapling, grasping, cauterizing, drilling, etc.

The flexible neck 1360 also preferably includes a forward collar 1382and a rear collar 1384. The forward collar 1382 comprises a unitarycylindrical member which may be fastened to a surgical head assembly,for example, with a pin placed through a hole 1383 in the collar 1382.The forward collar 1382 includes an annular flange 1385 against whichthe front portion 1366a of the top piece 1366 is placed. The rear collar1384 comprises two halves which are clamped together, for example, witha pin or other fastening device passing through a shaft into which therear collar 1384 is inserted, a pin or other fastener passing through ahole in the shaft and a hole 1387 in the rear collar 1384.

Referring now to FIGS. 49, 49A, and 49B, a preferred way in which thekerfs 1364 of the top portion 1366 may be offset from the teeth 1362 ofthe bottom portion 1368 is illustrated. In this embodiment, the kerfs1364 of the top section 1366 are angled outwardly at an angle theta₁which is greater than an angle theta₂ by which the kerfs 1364 of thelower portion 1368 of the flexible neck 1360 are angled outwardly. In ahighly preferred embodiment, as illustrated in FIG. 49, these angles are50° and 30°, respectively.

Referring now to FIG. 50, there is illustrated yet another preferredflexible neck mechanism of the present invention. In this embodiment,the flexible neck 1460 comprises two longitudinal sections 1466, 1468.One or both of the longitudinal sections include a slot 1470 thereinwhich may be a keyhole slot having a "T" shape as illustrated. The slot1470 receives a rigid straightening shaft having a cross-sectional areacorresponding to that of the slot 1470. In the embodiment of FIG. 50,the flexible neck 1460 is preferably injection molded plastic having apre-set arc, and is straightened by pushing the rigid straightener shaftthrough the flexible neck 1460. Other shapes, such as dovetails,"I-beam" shapes, etc. could be used for the slot 1470 and itscorresponding rigid straightening shaft.

This invention has been described in connection with severalparticularly preferred embodiments. It is to be understood, however,that one may accomplish the invention in a number of substantiallysimilar ways without departing from the scope and spirit of theinvention. Accordingly, it is to be understood that the invention is tobe better realized from the attached claims and their equivalents.Additionally, the present invention has been described above in terms ofrepresentative embodiments and figures which are intended to beillustrative and enabling to those of ordinary skill in the art, but notself-limiting. Furthermore, while many objects and advantages of theinvention have been set forth, it is understood and intended that theinvention is defined by the full scope of the following claims, and notby the objects and advantages.

What is claimed is:
 1. Means for articulatably mounting a surgicalcomponent to a shaft, comprising flexible neck means, said flexible neckmeans having a predetermined arcuate set, said flexible neck meansincluding an outer sleeve for retaining said surgical component in asubstantially linear relationship with respect to said shaft when saidsleeve covers said flexible neck means, said flexible neck meansassuming its predetermined arcuate set as it is withdrawn with respectto said sleeve, thereby articulating said surgical component withrespect to said shaft.
 2. The flexible neck means of claim 1, whereinsaid predetermined arcuate set is achieved by injection molding saidflexible neck means in said predetermined arcuate set.
 3. The means forarticulatably mounting a surgical component of claim 1, wherein saidouter sleeve comprises a rigid tube.
 4. The means for articulatablymounting a surgical component to a shaft of claim 1, said flexible neckmeans including at least one channel therethrough for slideablyreceiving a rigid straightening means for straightening said flexibleneck from its predetermined arcuate set to said substantially linearorientation.
 5. The means for articulatably mounting a surgicalcomponent to a shaft of claim 1, comprising a keyhole slot in saidflexible neck means and said shaft has a portion having across-sectional shape conforming to the cross-sectional shape of saidslot.